1. Technical Field
The present invention relates to liquid ejection apparatuses including a liquid ejecting head that ejects liquid, and more specifically to ink jet recording apparatuses including an ink jet recording head that ejects ink as an example of liquid.
2. Related Art
In an ink jet recording head which is a typical example of liquid ejecting head, ink is generally supplied from a liquid storing unit such as an ink cartridge that stores ink to a head body. Then, ink is ejected from nozzle openings as ink droplets by driving pressure generating units such as piezoelectric elements and heat generating elements.
Such an ink jet recording head has a problem that air bubbles contained in ink or air bubbles entrained in ink during attachment or removal of the liquid storing unit may enter the ink jet recording head, leading to an ejection failure such as missing dots. In order to solve such a problem, ink jet recording head may have a filter disposed at a position in a liquid flow path between an ink supply needle inserted into the ink cartridge and the ink jet recording head so as to remove the air bubbles and foreign matters in ink.
Such a filter disposed in the liquid flow path can prevent the air bubbles from entering the head body, however has a problem the air bubbles trapped in a filter chamber which is a space upstream of the filter are not easily discharged.
JP-A-2000-296622 and JP-A-2010-201829 propose to provide a wall made of an elastic member in a filter chamber at a position opposite a filter so as to deform toward and away from the filter.
However, in this configuration, there is a problem in that a large expensive suction unit having a high suction force is necessary to discharge the air bubbles trapped on the filter by suctioning ink from nozzle openings.
Such a problem exists not only in ink jet recording apparatuses but only in liquid ejection apparatuses ejecting a liquid other than ink.